once a boat on foils is going this fast, there must be the possibility of aero lift as well. Its complicated for a proa because it has to run both ways, but a bridgedeck configured as an ogival form between both hulls might work. Theres enough area available there to 'contribute' to lift this rather lightweight boat.

This is akin to the ground effect vehicles, otherwise aka as GEM, GEV, strongly researched by the Russians 20-30  years ago. What happens is, with a wing structure the conventional lift coefficient is around 1.2, and it has a lift centre variously 25% to 33% of the chord back from the leading edge.

Conventionally the top side of suction side of a wing contributes most to lift. But In ground effect, air becomes trapped beneathe the wing and the surface you are about to be flying over. So it pumps the lift coefficient to around the 2.2 value (from 1.2) up to around half the wingspan (in this case the bridgedeck). Because the additional lift comes from beneath the wings surface, it has the net effect of moving the aerodynamic centre to around 50% of the chord, weakening as the machine gets higher.

So stepping back a little
My suppositions are that, an aero profiled bridgedeck could/would contribute to lift. So if you were having trouble lifting off with foils alone, the deck could be used to assist. As an observation, it is also likely that the usual catamaran mesh deck would simply be allowing this force to be wasted. That even a flat deck without a cambered suction side (top) would contribute a Cl of around 1 (2.25-1.2) providing that the trailing edge is sufficiently close to the water. It must be pointed out however, that the weight of the deck be quite light, as its weight would deduct from that contribution to lift in circumstances where the force isnt great.

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